<!DOCTYPE html>



  


<html class="theme-next pisces use-motion" lang="zh-Hans">
<head>
  <meta charset="UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1"/>
<meta name="theme-color" content="#222">









<meta http-equiv="Cache-Control" content="no-transform" />
<meta http-equiv="Cache-Control" content="no-siteapp" />
















  
  
  <link href="/lib/fancybox/source/jquery.fancybox.css?v=2.1.5" rel="stylesheet" type="text/css" />







<link href="/lib/font-awesome/css/font-awesome.min.css?v=4.6.2" rel="stylesheet" type="text/css" />

<link href="/css/main.css?v=5.1.3" rel="stylesheet" type="text/css" />


  <link rel="apple-touch-icon" sizes="180x180" href="/images/apple-touch-icon-next.png?v=5.1.3">


  <link rel="icon" type="image/png" sizes="32x32" href="/images/favicon-32x32-next.png?v=5.1.3">


  <link rel="icon" type="image/png" sizes="16x16" href="/images/favicon-16x16-next.png?v=5.1.3">


  <link rel="mask-icon" href="/images/logo.svg?v=5.1.3" color="#222">





  <meta name="keywords" content="Hexo, NexT" />










<meta name="description" content="str和unicode的区别 str和unicode同属序列类型（sequence types），一共有7中序列类型，分别是str, unicode, list, tuple, bytearray, buffer xrange。 string直接用引号来表示，unicode在引号前加一个u。 1234567&amp;gt;&amp;gt;&amp;gt; import chardet as cd&amp;gt;&amp;gt;&amp;gt;">
<meta property="og:type" content="article">
<meta property="og:title" content="Python中的str与unicode">
<meta property="og:url" content="http://yoursite.com/2017/11/14/2017-11-14-1/index.html">
<meta property="og:site_name" content="Bits and Bytes">
<meta property="og:description" content="str和unicode的区别 str和unicode同属序列类型（sequence types），一共有7中序列类型，分别是str, unicode, list, tuple, bytearray, buffer xrange。 string直接用引号来表示，unicode在引号前加一个u。 1234567&amp;gt;&amp;gt;&amp;gt; import chardet as cd&amp;gt;&amp;gt;&amp;gt;">
<meta property="og:locale" content="zh-Hans">
<meta property="og:image" content="http://yoursite.com/2017/11/14/2017-11-14-1/1.jpg">
<meta property="og:updated_time" content="2017-11-14T15:21:08.568Z">
<meta name="twitter:card" content="summary">
<meta name="twitter:title" content="Python中的str与unicode">
<meta name="twitter:description" content="str和unicode的区别 str和unicode同属序列类型（sequence types），一共有7中序列类型，分别是str, unicode, list, tuple, bytearray, buffer xrange。 string直接用引号来表示，unicode在引号前加一个u。 1234567&amp;gt;&amp;gt;&amp;gt; import chardet as cd&amp;gt;&amp;gt;&amp;gt;">
<meta name="twitter:image" content="http://yoursite.com/2017/11/14/2017-11-14-1/1.jpg">



<script type="text/javascript" id="hexo.configurations">
  var NexT = window.NexT || {};
  var CONFIG = {
    root: '/',
    scheme: 'Pisces',
    version: '5.1.3',
    sidebar: {"position":"left","display":"post","offset":12,"b2t":false,"scrollpercent":false,"onmobile":false},
    fancybox: true,
    tabs: true,
    motion: {"enable":true,"async":false,"transition":{"post_block":"fadeIn","post_header":"slideDownIn","post_body":"slideDownIn","coll_header":"slideLeftIn","sidebar":"slideUpIn"}},
    duoshuo: {
      userId: '0',
      author: '博主'
    },
    algolia: {
      applicationID: '',
      apiKey: '',
      indexName: '',
      hits: {"per_page":10},
      labels: {"input_placeholder":"Search for Posts","hits_empty":"We didn't find any results for the search: ${query}","hits_stats":"${hits} results found in ${time} ms"}
    }
  };
</script>



  <link rel="canonical" href="http://yoursite.com/2017/11/14/2017-11-14-1/"/>





  <title>Python中的str与unicode | Bits and Bytes</title>
  








</head>

<body itemscope itemtype="http://schema.org/WebPage" lang="zh-Hans">

  
  
    
  

  <div class="container sidebar-position-left page-post-detail">
    <div class="headband"></div>

    <header id="header" class="header" itemscope itemtype="http://schema.org/WPHeader">
      <div class="header-inner"><div class="site-brand-wrapper">
  <div class="site-meta ">
    

    <div class="custom-logo-site-title">
      <a href="/"  class="brand" rel="start">
        <span class="logo-line-before"><i></i></span>
        <span class="site-title">Bits and Bytes</span>
        <span class="logo-line-after"><i></i></span>
      </a>
    </div>
      
        <p class="site-subtitle"></p>
      
  </div>

  <div class="site-nav-toggle">
    <button>
      <span class="btn-bar"></span>
      <span class="btn-bar"></span>
      <span class="btn-bar"></span>
    </button>
  </div>
</div>

<nav class="site-nav">
  

  
    <ul id="menu" class="menu">
      
        
        <li class="menu-item menu-item-home">
          <a href="/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-home"></i> <br />
            
            首页
          </a>
        </li>
      
        
        <li class="menu-item menu-item-archives">
          <a href="/archives/" rel="section">
            
              <i class="menu-item-icon fa fa-fw fa-archive"></i> <br />
            
            归档
          </a>
        </li>
      

      
    </ul>
  

  
</nav>



 </div>
    </header>

    <main id="main" class="main">
      <div class="main-inner">
        <div class="content-wrap">
          <div id="content" class="content">
            

  <div id="posts" class="posts-expand">
    

  

  
  
  

  <article class="post post-type-normal" itemscope itemtype="http://schema.org/Article">
  
  
  
  <div class="post-block">
    <link itemprop="mainEntityOfPage" href="http://yoursite.com/2017/11/14/2017-11-14-1/">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="name" content="Yang Zhicai">
      <meta itemprop="description" content="">
      <meta itemprop="image" content="/images/avatar.gif">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="Bits and Bytes">
    </span>

    
      <header class="post-header">

        
        
          <h1 class="post-title" itemprop="name headline">Python中的str与unicode</h1>
        

        <div class="post-meta">
          <span class="post-time">
            
              <span class="post-meta-item-icon">
                <i class="fa fa-calendar-o"></i>
              </span>
              
                <span class="post-meta-item-text">发表于</span>
              
              <time title="创建于" itemprop="dateCreated datePublished" datetime="2017-11-14T20:17:36+08:00">
                2017-11-14
              </time>
            

            

            
          </span>

          

          
            
          

          
          

          

          

          

        </div>
      </header>
    

    
    
    
    <div class="post-body" itemprop="articleBody">

      
      

      
        <h3 id="str和unicode的区别"><a href="#str和unicode的区别" class="headerlink" title="str和unicode的区别"></a>str和unicode的区别</h3><ol>
<li>str和unicode同属序列类型（sequence types），一共有7中序列类型，分别是str, unicode, list, tuple, bytearray, buffer xrange。</li>
<li><p>string直接用引号来表示，unicode在引号前加一个u。</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">&gt;&gt;&gt; </span><span class="keyword">import</span> chardet <span class="keyword">as</span> cd</span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>s = <span class="string">"你好"</span></span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>type(s)</span><br><span class="line">&lt;type <span class="string">'str'</span>&gt;</span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>u = <span class="string">u"你好"</span></span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>type(u)</span><br><span class="line">&lt;type <span class="string">'unicode'</span>&gt;</span><br></pre></td></tr></table></figure>
</li>
<li><p>直接输入的string常量会用<em>系统缺省编码</em>方式来编码，例如在GBK环境下，’你好’会编码成’/xc4/xe3/xba/xc3’，而在UTF-8环境下就成了’/xe4/xbd/xa0/xe5/xa5/xbd’。</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">&gt;&gt;&gt; </span>s</span><br><span class="line"><span class="string">'\xe4\xbd\xa0\xe5\xa5\xbd'</span></span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>u</span><br><span class="line"><span class="string">u'\u4f60\u597d'</span></span><br></pre></td></tr></table></figure>
</li>
<li><p>len(string)返回string的字节数，len(unicode)返回的是字符数。所以str是字节串，由unicode经过编码(encode)后的字节组成的，unicode才是真正意义上的字符串，由字符组成（一个字符可能占用计算机内的一个或多个字节）。</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">&gt;&gt;&gt; </span>len(s)</span><br><span class="line"><span class="number">6</span></span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>len(u)</span><br><span class="line"><span class="number">2</span></span><br></pre></td></tr></table></figure>
</li>
<li><p>str与unicode的转换<br>简单原则：只对str使用decode，只unicode使用encode，不同编码转换,使用unicode作为中间编码。</p>
<img src="/2017/11/14/2017-11-14-1/1.jpg">
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># str与unicode类型间的转换</span></span><br><span class="line">str  -&gt; decode('the_coding_of_str') -&gt; unicode</span><br><span class="line">unicode -&gt; encode('the_coding_you_want') -&gt; str</span><br><span class="line"></span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>cd.detect(s)</span><br><span class="line">&#123;<span class="string">'confidence'</span>: <span class="number">0.7525</span>, <span class="string">'language'</span>: <span class="string">''</span>, <span class="string">'encoding'</span>: <span class="string">'utf-8'</span>&#125;</span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>s = <span class="string">"你好"</span></span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>u = s.decode(<span class="string">"utf-8"</span>)</span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>u</span><br><span class="line"><span class="string">u'\u4f60\u597d'</span></span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>s1 = u.encode(<span class="string">"utf-8"</span>)</span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>s1</span><br><span class="line"><span class="string">'\xe4\xbd\xa0\xe5\xa5\xbd'</span></span><br><span class="line"><span class="meta">&gt;&gt;&gt; </span>type(s1)</span><br><span class="line">&lt;type <span class="string">'str'</span>&gt;</span><br><span class="line">&gt;&gt;&gt;</span><br></pre></td></tr></table></figure>
</li>
</ol>

      
    </div>
    
    
    

    

    

    

    <footer class="post-footer">
      

      
      
      

      
        <div class="post-nav">
          <div class="post-nav-next post-nav-item">
            
          </div>

          <span class="post-nav-divider"></span>

          <div class="post-nav-prev post-nav-item">
            
              <a href="/2017/11/14/2017-11-14-2/" rel="prev" title="2017-11-14-2">
                2017-11-14-2 <i class="fa fa-chevron-right"></i>
              </a>
            
          </div>
        </div>
      

      
      
    </footer>
  </div>
  
  
  
  </article>



    <div class="post-spread">
      
    </div>
  </div>


          </div>
          


          

  



        </div>
        
          
  
  <div class="sidebar-toggle">
    <div class="sidebar-toggle-line-wrap">
      <span class="sidebar-toggle-line sidebar-toggle-line-first"></span>
      <span class="sidebar-toggle-line sidebar-toggle-line-middle"></span>
      <span class="sidebar-toggle-line sidebar-toggle-line-last"></span>
    </div>
  </div>

  <aside id="sidebar" class="sidebar">
    
    <div class="sidebar-inner">

      

      
        <ul class="sidebar-nav motion-element">
          <li class="sidebar-nav-toc sidebar-nav-active" data-target="post-toc-wrap">
            文章目录
          </li>
          <li class="sidebar-nav-overview" data-target="site-overview-wrap">
            站点概览
          </li>
        </ul>
      

      <section class="site-overview-wrap sidebar-panel">
        <div class="site-overview">
          <div class="site-author motion-element" itemprop="author" itemscope itemtype="http://schema.org/Person">
            
              <p class="site-author-name" itemprop="name">Yang Zhicai</p>
              <p class="site-description motion-element" itemprop="description"></p>
          </div>

          <nav class="site-state motion-element">

            
              <div class="site-state-item site-state-posts">
              
                <a href="/archives/">
              
                  <span class="site-state-item-count">2</span>
                  <span class="site-state-item-name">日志</span>
                </a>
              </div>
            

            

            

          </nav>

          

          <div class="links-of-author motion-element">
            
          </div>

          
          

          
          

          

        </div>
      </section>

      
      <!--noindex-->
        <section class="post-toc-wrap motion-element sidebar-panel sidebar-panel-active">
          <div class="post-toc">

            
              
            

            
              <div class="post-toc-content"><ol class="nav"><li class="nav-item nav-level-3"><a class="nav-link" href="#str和unicode的区别"><span class="nav-number">1.</span> <span class="nav-text">str和unicode的区别</span></a></li></ol></div>
            

          </div>
        </section>
      <!--/noindex-->
      

      

    </div>
  </aside>


        
      </div>
    </main>

    <footer id="footer" class="footer">
      <div class="footer-inner">
        <div class="copyright">&copy; <span itemprop="copyrightYear">2017</span>
  <span class="with-love">
    <i class="fa fa-user"></i>
  </span>
  <span class="author" itemprop="copyrightHolder">Yang Zhicai</span>

  
</div>


  <div class="powered-by">由 <a class="theme-link" target="_blank" href="https://hexo.io">Hexo</a> 强力驱动</div>



  <span class="post-meta-divider">|</span>



  <div class="theme-info">主题 &mdash; <a class="theme-link" target="_blank" href="https://github.com/iissnan/hexo-theme-next">NexT.Pisces</a> v5.1.3</div>




        







        
      </div>
    </footer>

    
      <div class="back-to-top">
        <i class="fa fa-arrow-up"></i>
        
      </div>
    

    

  </div>

  

<script type="text/javascript">
  if (Object.prototype.toString.call(window.Promise) !== '[object Function]') {
    window.Promise = null;
  }
</script>









  












  
  
    <script type="text/javascript" src="/lib/jquery/index.js?v=2.1.3"></script>
  

  
  
    <script type="text/javascript" src="/lib/fastclick/lib/fastclick.min.js?v=1.0.6"></script>
  

  
  
    <script type="text/javascript" src="/lib/jquery_lazyload/jquery.lazyload.js?v=1.9.7"></script>
  

  
  
    <script type="text/javascript" src="/lib/velocity/velocity.min.js?v=1.2.1"></script>
  

  
  
    <script type="text/javascript" src="/lib/velocity/velocity.ui.min.js?v=1.2.1"></script>
  

  
  
    <script type="text/javascript" src="/lib/fancybox/source/jquery.fancybox.pack.js?v=2.1.5"></script>
  


  


  <script type="text/javascript" src="/js/src/utils.js?v=5.1.3"></script>

  <script type="text/javascript" src="/js/src/motion.js?v=5.1.3"></script>



  
  


  <script type="text/javascript" src="/js/src/affix.js?v=5.1.3"></script>

  <script type="text/javascript" src="/js/src/schemes/pisces.js?v=5.1.3"></script>



  
  <script type="text/javascript" src="/js/src/scrollspy.js?v=5.1.3"></script>
<script type="text/javascript" src="/js/src/post-details.js?v=5.1.3"></script>



  


  <script type="text/javascript" src="/js/src/bootstrap.js?v=5.1.3"></script>



  


  




	





  





  









<script src="//cdn1.lncld.net/static/js/3.0.4/av-min.js"></script>
<script src="//unpkg.com/valine/dist/Valine.min.js"></script>



  





  

  

  

  
  

  

  

  

</body>
</html>
